/Engine/Source/Runtime/Slate/Public/Framework/Application/SlateApplication.h
Apply any requests from the Reply to the application. E.g. Capture mouse
void ProcessExternalReply ( const [FWidgetPath](API\Runtime\SlateCore\Layout\FWidgetPath) & CurrentEventPath, const [FReply](API\Runtime\SlateCore\Input\FReply) TheReply, const int32 UserIndex, const int32 PointerIndex )